Process for welding dissimilar metals.



I F. w. ROGERS. PROCESS FOR WELDING DISSIMILAR METALS.

APPLICATION FILED DBO. 26, 1911.

Patented Mar. 18, 1913.

. To all whom it may) concern:

UNITED STATES PATENT oEmcE.

FREDERICK W. ROGERS, OF BEAVER DAM, WISCONSIN, ASSIGNOR TO MALLEABLEIRON RANGE COMPANY, OF BEAVER DAM, WISCONSIN, A CORPORATION OFWISCONSIN.

' PROCESS FOR WELDING DISSIMILAR METALS,

Be it known that I, FREDERICK W. ROGERS, a citizen of the United States,and resident ofBeaver Dam, in the county of Dodge and State ofWisconsin, have invented new and useful Improvements 'in'PrOcesses forWelding Dissimilar Metals, of which the following is a description,reference being had to the accompanying drawings, which are a p-art ofthis specification.

My invention relates to a process for welding dissimilar metals and theproduct re-' sulting therefrom, and refers particularly (although notexclusively) to the welding of relatively corrosive and non-corrosivemetals, such as iron or steel and copper.

I. am aware that it has heretofore been possible to weld dissimilarmetals, such ascopper and steel, but this operation has al-' ways beendifficult to carry out, in that itnecessitates the melting ofcomparatively large amounts of metal on the one hand," or on the .otherconsists in rolling together the highly heated metals.

It is the object of my invention toconduct the welding operation in suchmanner that the union of the metals is quickly and easily attainedwithout the use of cumbersome apparatus. In order to accomplish thisresult I bring the two metals to be welded into contact with each otherand then partially or wholly fuse the metal of lower melting point byapplying heat thereto through the medium of a welding plate of highermelting point. Pressure is preferabl applied to the metals at the sametime, an the metal between the welding plate and the metal of highermelting point is united either to the latteralone or to the latter andthe welding plate, by an alloying action. f In carrying out my process'Iordinarily employ anelectric current as the source of heat, and for theprincipal metals I use sheets of steel and-copper, while the-weldingplate may be steel, nickel, German silver,

' Monel metal, or any similar metal or alloy which hasa higher meltingpoint than the copper and which preferably has a low heat conductivity.I

,When the electrodes of a welding machine are applied to the weldingplate and the steel sheet, the flow of current is allowed to heat thewelding plate and the steel to a temperature approximately correspond-Specification of Letters Patent.

Application filed December 26, 1911. Serial No. 667,600.

Patented Mar. 18', 1913.

ing to the melting point of thecopper, and at the points of junctionbetween the weldingplate and the copper on the one hand and the copperand the steel on the other,

the. temperature is apt to increase somewhat on account of the increasedresistance .at these points. The copper is thereby alloyed wlith andwelded to the steel and the welding ate. Although I prefer to employ anelectric current as the source of heat, it will be evident that anyother similar heating means, such as a blow pipe, preferably used-inconnection with pressure applied to the plates, may be employed.Moreover, it is possible to so conduct the process that the weldingplate is separated from the copper by an infusible layer of material sothat the welding plate may be removed after the opera-' tion is comleted.

These an other advantages of my -invention will be more readilyunderstood by reference to the accompanying drawing, which shows apreferred form of apparatus for carrying out'my process and also illustrates the product resulting therefrom.

In the accompanying drawing, in which the same reference charactersindicate the same parts in the several views: Figureil is a side view ofthree metallic plates,the'lower plate being the steel or iron plate, theupper being the welding plate, and the intermediate plate being a plateof copper; Fig. 9; is a cross sectional view thereof taken on ,line 2-2of Fig. 1; Fig. 3 is an edge view of the three'plates shown in Fig. 1,and

illustrates a cut partly through the plates,

the out being made on line 3.3 of Fig. 1 and the cut portions beingpried apart; an Fig. 4 is a vertical section through the three plates,and -also.illustrates a pair of elec-.

three pieces of metal are placed between the electrodes 7 and 8 of anelectric welding machine.

'i The. welding plate 6, while preferably formed of Monel metal, mayalso be made of iron or steel, nickel, German silver, or the like, thegeneral characteristic of the welding plate being that it shall possessa higher melting point (and also preferably a lower heat Conductivity)than the copper or like metal.

The three pieces of metal are pressed firmly together by the electrodesto form an intimate contact of the metals at the spot to be welded, andthe current is then turned on to form the weld, or the plates may beclamped together in any manner desired and the electrodes positioned toform an are between plates and the electrodes thus applying heat to theplates. \Vhen the current has thus been turned on, the heat generated bythe resistance of the two outer plates will be concentrated and confinedwithin a small area, and suflicient heat will thus be transmitted to theintermediate plate at a point between the electrodes to melt a partofthe plate 5 and form a button-like portion 9 consisting of the metal ofthe plate 5 fused or alloyed with the inner surfaces of the plates 4 and6. On account of imperfect contact between the plate 5 and the innersurfaces of the plates 4 and 6 the electrical resistance, andconsequently the temperature, increases somewhat at these lines ofjunction, thereby facilitating the alloying action. As a result of thespecific embodiment of my process as described, a spot weld is madewhich unites the three metals together. This process is of particularadvantage in welding water reservoirs to the end heating plates ofstoves and ranges, in order to provide an intimate and close contactbetween the inner wall of the water reservoir andthe end plate of thestove or range, so that heat is readily and quickly transmitted to thewater within the reservoir. The spot welds provide an integral metallicheat conductor between the heating chamber of the range and the waterwithin the reservoir.

Although the apparatus or means which I have illustrated is for'thepurpose of spot welding sheets of copper and steel, it will be apparentthat other apparatus could readily be employed to weld the metals over agreater area.

It will also be clear to those skilled'in the art that instead of usingelectrodes to perform the welding operation, a blow pipe applied to thewelding plate, or a pair of blow pipes applied to the welding plate andthe sheet steel might readily be used, the copper thus being meltedbetween the two metals and alloying with the same so that a weld isformed. The use of-such heating means is preferably accompanied by theap lication of pressure sothat the various p ates are snugly contactedwith each other before the welding is performed.

Other variations of the exact processes the latter will be fused which Ihave described could readily be .made without departing from either thespirit or scope of my invention.

lVhat I claim is,

l. A process of welding two unlike metals, possessing different physicalproperties, which consists in utilizing a binding metal which possessesphysical properties different from at least one'of the other metals tobe welded, and placing one of said metals to be welded between thebinding metal and the other metal to be welded, and subjecting the threecontacting metals to a welding heat sufiicient to cause an integral weldbetween the two unlike metals.

2. A process of welding two unlike metals, possessing different physicalproperties, which consists in utilizing a binding metal possessingphysical properties different from at least one of the other metals, andplacing one of the metals to be welded between the binding metal and theother metal to be welded, and subjecting the three contacting metals toa welding heat sufficient to cause an integral weld between the threemetals,

the interposed metal freely fiuXing with the iron or steel, whichconsists in utilizing a sheet of binding metal possessing physicalproperties different from at least one of the metals to be welded,placing the copper between the binding metal and the other metal, andsubjecting the three contacting metals to a welding heat sufficient tocause a weld between the three metals, the interposed sheet of copperfreely fluxing with the other metals at the point of weld.

5. A process of welding sheet copper to iron or steel, which consists inutilizing a sheet of Monel metal and placing the sheet copper betweenthe Monel metal and the iron or steel, and subjecting the threecontacting metals toa welding heat suflicient to cause a weld betweenthe three metals, the interposed sheet of copper freely fluxing with theother metals at the point of weld.

6. The process of uniting dissimilar metals, which consists inconducting heat through an auxiliary metal in contact with one of saidfirst mentioned metals, whereby together, substantially as described.

.10 Y sists in applying to the metal having-the '7. The process ofuniting dissimilar metals, such as copper and steel, which consistslower melting point, as copper, whereby the latter will become ineltedand fuse with the a second metal, as ,steel, substantiallyv asdescribed.

8. The process of uniting dissimilar metals, such as copper and steel,which conlower melting point, as copper, a welding plate having a highermelting point than the latter, and conducting heat through 1 saidwelding plate, whereby the metal of lower melting point, as copper, isfused with the l per a welding plate having a higher melting metal ofhigher melting polnt, as steel, substantially as described.

- 9.- The process of uniting copper and steel, which consists inapplying to the copper a welding plate having a higher melting pointthan that of the copper, and passing an electric current through thethree metals in contact with each other, whereby the copper, is meltedand becomes fused with-the steel, substantially as'described. l

10. The process of unitingcopper and steel, which consists in applyingto the coppoint and a lower heat conductivity than the copper, andapplying heat to said welding plate, whereby the copperlis melted andfused with said steel, substantially as described.

11; The process of uniting copper and steel, which consists in'applyingto the copper a welding plate having a higher melting point anda lower heat conductivity than the copper, applying pressure to themetals and passing an electric current through said metals, whereby thelatter are heated, and the copper is melted and unites with said steel,substantially as described.

12. A process of welding two metals of dissimilar heat conductivity,consisting of placing the two metals together and also placing a thirdmetal of less heat conductivity than the metal of higher conductivityagainst the said metal of higher conductivity and submitting the threemetals to a welding heat.

In testimony whereof, I afiix my signature in presence of two witnesses.

FREDERICK W.. ROGERS.

Witnesses: I

.PETER M. KETTENHOFEN, SILAs MCCLURE.

